During the IX Asian Games held during 19th Nov. — 4th Dec. 1982 in New Delhi, a large fleet of automobiles were pressed into service, in addition to that already available in the city.
The additional influx of the automobiles was expected to cause increments in the levels of lead in the ambient air due to exhaust emission. A study was carried out during October through December 1982 on the Nerium indicum and Eucalyptus rostrata plants which grow on the road-divider-fence and the road- boundary of the Ring Road respectively. The Ring Road is one of the major roads in the capital, of about 52 Km. with varying degree of traffic density at different intersections.
Seven major traffic intersections on the Road Ring were chosen for the study of the distribution of lead in the N. indicum and E.rostrata plants. Lead samples of these plants were collected in the months of October, November and December 1982 and were analysed for the lead content by using Atomic Absorption Spectrophotometric technique.
It was observed that the quantities of lead in the plants were higher in the month of November as compared with that of October and there was again reduction in the month of December which was more or less comparable to that of the values obtained in October. Significance of the findings is discussed in the paper.

INTRODUCTION

The major source or atmospheric lead pollution is the exhaust emission from automobiles. Antiknock lead alkyls in the form of tetraethyl lead (TEI.) and tetra methyl lead (TML) are added to the petrol. In India, the amount of lead added to petrol ranges from 0.0006g to 0.207g per litre and most of this is emitted into the environment through automobile exhaust elluent.

The summary of the toxicology of lead has been given by Bryee-Smith (I). Among other things, one of the interesting aspects of lead from automobile exhaust is its accumulation in vegetation along the narrow patches on road sides, fall out of lead and its uptake by crops has been described by Chamberlain (2.) Warren and Delavault found values of lead as high as 3100 ppm in the ash of the Douglas fir near highways, whereas background values were only 40 ppm (3). Cannon and Bowles found that the influence of lead could be detected upto 200 m from the road, and that values upto 1000 ppm were obtained from samples nearest to the road (4).

Distribution of lead in the pasture harbage and several other crop plants has been reported by Mitchell and Reith Goodman and Roberts Burkitt, Lester and Nickles Williams, Tyell, llovmand and Mossbaek, (5,6,7,8,9).

The work of Page at al. (10) on vegetables grown near highways showed that although there was an elevation in content of lead in the soil within 50m of the road (up to 118 ppm pb) the relatively high values in vegetation (up to 8 ppm dry weight in strawberries) were due to obsorption from aerial lead, and not due to uptake from soil via the root system.

Although most of the lead from automobile exhaust is ultimately deposited on the ground, the environmental air can often contain appreciable amounts of this pollutant. Lead concentrations in ambient air of live major cities in India (II) are giver in Table No. 1.

IX Asian Games were held in New Delhi during 19th Nov. to 4th Dec, 1982. To meet the extra demand of transportation of the players, officials and the general public during the Games, a large number of vehicles were pressed into the service in addition to the already available in the city. An additional influx of the automobiles and traffic was expected to cause increments in the levels of lead in the ambient a jus to increased automobile exhaust emissions.

The present paper deals with the studies carried out on the accumulation of lead by the N. iudicum and E. rostrata plants at the Ring Road in the city of Delh during the months of October, November and December, 1982. These plants grow on the road-divider- fence (N. indicum) and on the road-boundary E. rostrata of the Ring Road, which is one the major express high ways of the Capital.

Table 1 : Lead corcentration in the ambient air of five major cities in India (after pandya at al,83).

Sr. No.	Name of the city and Year		Lead content in Average	mg/m3 air Maximum
1.	BOMBAY	(1968)	0.496	1.563
		(1978)	0.072-0.656	0.656
2.	CALCUTTA	(1969)	1.770	5.199
3.	DELHI	(1968)	0.350	1.500
4.	AHEMDABAD Residential area	(1978)	0.510	2.00
5.	KANPUR CITY	(1979)	0.619	4.751
6.	Traffic Corners Ahmcdabad		7.00	13.30

MATERIAL AND METHODS

Leaves of the Nerium Indicum Mill and euealyptus rostrata L. plants were collected in the last week of October, November, and December, 1982 from the seven major traffic intersections on the Ring Road in the city of Delhi (Table No. 2 and Figure No. 1), Precautions were taken to ensure proper randamisation while collecting the samples in the polythene bags. Samples were washed in the laboratory by glass distilled water and then dried for 24 hours at1OO°c ± 2°c in hot air oven. One gram dried and powdered plant material from each sample was digested, In duplicate, in the laboratory by using AR Grade, triacld mixture-until a clear solution was obtained which was then made upto 100 ml by using the glass distilled water. The values of lead were obtained by feeding the djgested samples to the atomic absorption spectrophotometer (Perkin-Elmer Make, Model 703)fitted with hollow cathode lamp (263nm) for lead. Bank was run simultaneously along with the samples under identical conditions and the necessary blank corrections were made in the sample values which are expressed as ppm (parts per million).

Table 2 : escription of spots selects for the collection of leaf samples of N, 1NDK.UM and E, ROSTRATA plants on the Ring Road, Delhi,during October, November and December, 1982.

Sr. No.	Name of the traffic Intersection	Description
1.	AZADPUR	Located near (the Chatrnnal football studim, Model Town, Gateway for the trafflc from Haryana. Punjab, III'., J, A; K. States and U.T. Chandigarh. Into the city.
2.	PUNJABI BAGH	one of the major traffic junetlone on Ring Road in West Delhi, traffic from Haryana and Rajasthn states enter the city at this point, Oil depots in close vicinity.
3.	DHAULA KUAN	Entry for traffic frome.Rajasthan and Haryana One of the Roads of the rquaed lead to Talkntorn Stadium for Swimming and BaskeBall events, and other to Delhi Air Port Harbaksh Stadium and Nicholson Raagofor Equestrian events
4.	MULCHAND	Major traffic intersection in South Delhi. Located near the Main Stadium of the Games, Jawaharlal Nehru Stadium. One road from here also lead to the Games Village.
5.	ASHRAM	Agra-Mathura Road (National Highway) intersect the Ring Road at this spot which has the traffic from U.P\, Haryana, Rajasthan and the Stale of south, west and Central India
6.	INDRAPRASTHA	This site is surrounded by many stadia where the Gaines were held. To the east are I. P. Indoor Stadium and Yamuna Velodrome; to the north is Ambedkar Stadium; to the west (about 3 km) arc Shivaji Stadium and Railway Stadium;and to the south are Hall of spoils, National Stadium and Delhi Golf Club. Besides trailic due to the Games, the traffic From eastern suburbs and u.p'. State enters the city at this point
7.	KHYBER PASS (MALL ROAD)	This Spot is situated near the University Stadium for Archery and Hand Ball events. The traffic to and from the Spot No. 1 passes through this site.